U.S. Pat. No. 8,155,415 discloses an apparatus and method for expanding the field of view of a truncated computed tomography (CT) scan. An iterative calculation is performed on the original CT image to produce an estimate of the image. The calculated estimate of the reconstructed image includes the original image center and an estimate of the truncated portion outside the image center. The calculation uses an image mask with the image center as one boundary.
U.S. Pat. No. 8,107,708 discloses a method for correcting truncation artifacts in a reconstruction method for computed tomography recordings. The projection images are recorded by an X-ray image detector being extended by determining the attenuation of the radiation outside the projection image for pixels. Non-horizontal filter lines are extended by transaxial and axial artificial extension of the X-ray image detector for the purposes of truncation correction.
U.S. Pat. No. 7,756,315 discloses a method for expanding a field-of-view of a volumetric computed tomography scan. The method includes identifying truncated views having projection truncation and non-truncated views without projection truncation based on an average value of one or more edge channels. An estimated missing projection is calculated for each of the truncated views based on at least one neighboring non-truncated view. A projection profile is calculated for each of the truncated views based on the estimated missing projection, and the projection profile provides at least one of attenuation data and projection data for an area outside a field-of-view.
U.S. Pat. No. 5,278,887 discloses an apparatus and method for reducing the dosage of X-rays during a fluoroscopic procedure. A filter member is used to selectively attenuate the X-ray radiation striking a patient's body. The filter member allows unattenuated X-rays to image an area of interest selected by a physician, thus producing a high intensity, low noise image. Areas surrounding the area of interest are imaged with attenuated radiation producing a less intense, more noisy image.
U.S. patent application Ser. No. 12/990,285 discloses a method of using non-attenuation corrected PET emission images to compensate for incomplete anatomic images. A segmented contour of a non-attenuation-corrected (NAC) PET image is used to identify a contour of the truncated region. An appropriate tissue type is used to fill in truncated regions of a truncated CT or MR image or the attenuation map. The corrected attenuation map is then used to generate an attenuation-corrected PET image of the patient or a region of interest.
U.S. patent application Ser. No. 13/113,714, which is hereby incorporated by reference in its entirety, discloses X-ray imaging systems and methods that utilize an imaging apparatus that includes an emitter emitting X-rays through an object and a receiver receiving the X-rays. A control circuit controls the emitter and processes the X-rays received by the receiver to generate X-ray images of the object. The control circuit controls a display to display an initial view of the object. The display of the initial view of the object is modifiable by a user. The imaging apparatus is controlled to generate an X-ray position image of the object based upon the user modification of the display of the initial view. The display is controlled to display a positioning image. The display of the positioning image is modifiable by a user and the imaging apparatus is controlled to generate an X-ray image of the object based upon the user modification of the display of the positioning image.